Cement-based airtight membrane for Nearly Zero Energy and Passivhaus Buildings

Product variations:
ARGOTEC® HERMETIC is a super-flexible, single-component, polymer modified mortar (PCC) for bonding different materials, formulated with special polymers, binders and multifunctional fillers that give it extraordinary elasticity, airtightness and adhesion to a wide range of substrates.

Installation video



  • Mainly on the inside face of the building shell, contributing to the airtightness of the building.
  • Union between supports of the same or different materials, such as roofs and enclosures, floors and enclosures, window jambs, pipe frames, especially suitable as an airtight layer in nearly zero-energy and passivhaus buildings.

Advantages & Benefits

  • High level airtight properties.
  • Highly flexibility and has an ability to re-form against differential movements.
  • Cures and hardens without cracking.
  • Outstanding Adhesion
  • Excellent value for money
  • Excellent workability.
  • Impervious to water.
  • Permeable to water vapour.
  • It can be applied with a brush, paintbrush or roller.


  • Steel.
  • Aluminium.
  • Concrete block.
  • Mortar renderings.
  • Concrete/Screed.
  • Brick.
  • PVC sheets.
  • Laminated plasterboard.

Substrate preparation

  • The substrates must be clean and sound, free of grease, paint or other substances that would prevent proper adhesion.

Instruction for Use

  • Knead ARGOTEC HERMETIC with the appropriate amount of water to achieve the optimum consistency (homogeneous, creamy, lump-free mixture with a thick paint-like appearance). The kneaded mortar should always be applied in a minimum of two coats so that a homogeneous coating is obtained.
  • Apply the first layer of mortar with a brush, pressing on the substrate to ensure adherence in thicknesses of less than 2 mm, trying to ensure that the mortar covers the entire surface. The following coats shall be applied by brush or airless machine and in perpendicular directions once the previous coat has dried (4-24 h depending on environmental conditions)”.


  • Preferably apply to the positive layer (the one that receives the water pressure).
  • Avoid accumulating too much material in joints or fillers to prevent cracking.
  • Singular points shall be dealt with in an appropriate manner.
  • Do not apply when there is a risk of frost, rain, strong wind or direct sunlight.
  • Do not apply below 5°C or above 30°C.
  • Protect the cool surface from direct sun, rain and especially draughts.

Handling, storage and preservation

  • It is packaged in a 4 kg plastic jar that allows it to be stored for 12 months in its original sealed packaging, safe from dampness.

Safety and hygiene

  • Disposal of the product and its packaging must be carried out in accordance with current legislation and is the responsibility of the end consumer of the product.
  • For any information concerning safety issues in the use, handling, storage or disposal of chemical residues, users should refer to the most recent version of the MSDS.


  • The information contained in this document and any other advice provided, are given in good faith, based on DANOSA's current knowledge and experience when products are properly stored, handled and applied, in normal situations and in accordance with the recommendations of DANOSA. The information applies only to the application (s) and the product (s) to which reference is expressly made. In case of changes in the parameters of the application, or in case of a different application, consult the DANOSA Technical Service before using the DANOSA products. The information contained herein does not exonerate the responsibility of the building agents to test the products for the application and intended use, as well as their correct application in accordance with current legal regulations. The product images used in our communications are indicative and may differ slightly in color and aesthetic appearance in relation to the final product.Orders are accepted in accordance with the terms of our current General Sales Conditions.DANOSA reserves the right to modify, without prior notice, the data reflected in this documentation.Website: E-mail: Telephone: +34 949 88 82 10


  • Appearance: Powder
  • Colour: Grey
  • Weight (kg): 4
  • Yield (kg/m²): 2 kg/m² y 2 mm de espesor
  • Performance in mm thickness (kg/m²): 1,2
  • Product code: 350246

Technical Data

Concept Value Standard
Mass per unit area (nominal) (kg/m²) 4 -
Capillary Absorption (kg/m²h0.5) W2 -
Adhesion after thermal compatibility (N/mm²) ≥ 0,8 -
Direct Tensile Adhesion (N/mm²) ≥ 0,8 -
Mixing water (%) 23/25 -
Thermal conductivity declared (W/mK) 0,47 -
Bulk density (kg/L)v ~ Value 1,20 ± 0,05 -
Fresh mass density (kg/L) ~ Value 1,40 ± 0,05 -
Maximum thickness (mm) 2 -
Minimum thickness (mm) 1 -
Grain size range (mm) ~ value 0/0,03 -
Water vapour permeability (m) Clase I -
Reaction to fire A1 -
Compacting resistence 28 days (N/mm²) ≥ 7,5 -
Compacting resistence 7 days (N/mm²) ≥ 3 -
Hazardous substances Ver HS -

Addtitional Technical Data

Concept Value Standard
CO2 permeability Pasa -